xref: /freebsd/usr.sbin/ipfwpcap/ipfwpcap.8 (revision d056fa046c6a91b90cd98165face0e42a33a5173)
1.\" Copyright (c) 2006 Niclas Zeising
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25.\" $FreeBSD$
26.\"
27.Dd May 22, 2006
28.Dt IPFWPCAP 8
29.Os
30.Sh NAME
31.Nm ipfwpcap
32.Nd "copy diverted packets to a file in tcpdump format"
33.Sh SYNOPSIS
34.Nm
35.Op Fl dr
36.Op Fl b Ar maxbytes
37.Op Fl p Ar maxpkts
38.Op Fl P Ar pidfile
39.Ar portnum
40.Ar dumpfile
41.Sh DESCRIPTION
42The
43.Nm
44utility is used to copy diverted packets to a file in
45.Xr tcpdump 1
46format.
47The interesting packets are diverted by
48.Xr ipfw 8
49to a port on which
50.Nm
51listens.
52The packets are then dropped unless
53.Fl r
54is used.
55.Pp
56The options are as follows:
57.Bl -tag -width Ds
58.It Fl d
59Turns on extra debugging messages.
60.It Fl r
61Writes packets back to the divert socket.
62.It Fl rr
63Indicates that it is okay to quit if
64.Ar maxbytes
65or
66.Ar maxpkts
67are reached.
68Diverted packets will silently disappear if nothing is listening on the
69divert socket.
70.It Fl b Ar maxbytes
71Stop dumping after
72.Ar maxbytes
73bytes.
74.It Fl p Ar maxpkts
75Stop dumping after
76.Ar maxpkt
77packets.
78.It Fl P Ar pidfile
79File to store PID number in.
80Default is
81.Pa /var/run/ipwfpcap.portnr.pid .
82.El
83.Pp
84The
85.Ar portnum
86argument specifies which
87.Xr divert 4
88socket port to listen on.
89The
90.Ar dumpfile
91argument is the path to the file to write captured packets to.
92Specify
93.Sq Li -
94to write to stdout.
95.Sh EXIT STATUS
96.Ex -std
97.Sh EXAMPLES
98.Dl ipfwpcap -r 8091 divt.log &
99.Pp
100Starts
101.Nm
102as a background job listening to port 8091 and reflecting the packets
103back to the socket.
104.Pp
105.Dl ipfw add 2864 divert 8091 ip from 192.168.1.101
106.Pp
107Example
108.Xr ipfw 8
109rule to divert all packets from 192.168.1.101 to port 8091.
110See
111.Xr ipfw 8
112for details.
113.Sh SEE ALSO
114.Xr tcpdump 1 ,
115.Xr pcap 3 ,
116.Xr divert 4 ,
117.Xr ipfw 8
118.Sh HISTORY
119The
120.Nm
121utility first appeared in
122.Fx 7.0 .
123.Sh AUTHORS
124.An -nosplit
125.Nm
126was written by
127.An P. Kern Aq pkern@cns.utoronto.ca .
128This manual page was written by
129.An Niclas Zeising Aq lothrandil@n00b.apagnu.se .
130